I was referred to this journal article on "Economics of POW Camp" as a classic paper in economics. I can see why economists get their students to read it. The article describes a number trade arrangements that emerged spontaneously, and as a result serve to reinforce economic principles. It's long, but interesting.
The article was written very shortly after the end of the war, so memories are fresh. The author was a former POW, with first hand knowledge. The diction and prose is very sophisticated. It uses relatively complex sentence constructions, that are surprisingly easy to understand. I don't know anyone who writes like that these days. I know I don't, because I'm always worried about making complex ideas understandable. Consequently, I write wordy, informal text. The writing in the article is formal and preserves the complexity.
It talks about how systems of trade, barter, and commerce were developed around rations in POW camps in Germany during World War II. Note that these are POW camps and not concentration camps, so the residents were actually fed. The soldiers received basic rations from their German captors, so their basic needs were looked after. The Red Cross also distributed rations that included cigarettes, chocolate bars, tea, and so on. Occasionally, care packages would arrive in the post.
These were soldiers who were used to working in a hierarchy and ranks were preserved and respected within the camps. As well, sections of the camp organized nationally, partly due to Germans having separate camps for some countries, but also the military shadow organization establishing chains of command and lines of communication.
While people did initially barter and trade for goods, the cigarette became the basic unit of currency to establish fair prices across permanent camps and limit arbitrage.
The British eventually set up a store and a restaurant! People came to the restaurant for prepared foods and entertainment.
Probably the most interesting POW camp that I have heard about was the one after the Korean War. "They Chose China" is a film about US soldiers who decided to stay in China after the Korean War. Video of the film is available on YouTube
. These men went on to have wives and families. Some went back to the US after some years, but others never returned. Anyhow, the POW camp was run by the Chinese in consultation with some officers were who selected to represent the men. The Chinese asked the representatives about what Americans liked, and for the most part they provided. They had games, sports, crafts, activities... the list is endless. At one point they had an Olympic games. The Chinese treated the soldiers as guests and provided lots of education about communism and Chinese language. After all that good treatment, it's not surprising that some chose to say behind, especially ones who didn't have good prospects back in the US and UK.